Canon's very quiet time going round about church (7)
I believe the answer is:
precept
'canon's' is the definition.
(thesaurus)
'very quiet time going round about church' is the wordplay.
'very quiet' becomes 'pp'.
'time' becomes 't'.
'going round' indicates putting letters inside.
'about' becomes 're' (regarding**).
'church' becomes 'ce' (abbreviation for Church of England).
'pp'+'t'='ppt'
're'+'ce'='rece'
'ppt' enclosing 'rece' is 'PRECEPT'.
(Other definitions for precept that I've seen before include "Rule or principle" , "Rule of conduct or doctrine" , "Moral rule" , "Rubric" , "General rule for behaviour" .)